The long-term objective of the proposal is to contribute to the development of objective criteria for the clinical assessment of voice and laryngeal dysfunction. Voice disorders caused by a variety of laryngeal conditions seriously interfere with the social/economic functioning of a significant portion of the population. Specific aims are to compare voices representing the following laryngeal conditions: vocal nodules/discrete polyps, polypoid degeneration, unilateral vocal fold paralysis, and functional dysphonia, (along with a normal control group) on the basis of acoustic, perceptual, and laryngeal waveform measures. Simultaneous recordings of the vowel /a/ will be obtained using a digital sonograph and a laryngograph. Traditional measures including open quotient and speed quotient (laryngeal waveform) as well as harmonic-to-noise ratio (acoustic) will be correlated with perceptual ratings of specific voice types. The results should provide information which will assist both the otolaryngologist and voice therapist in the evaluation and management of voice problems.